Problem: $\dfrac{9}{2} - \dfrac{5}{12} = {?}$
Answer: $ = {\dfrac{9 \times 6}{2 \times 6}} - {\dfrac{5 \times 1}{12 \times 1}} $ $ = {\dfrac{54}{12}} - {\dfrac{5}{12}} $ $ = \dfrac{{54} - {5}}{12} $ $ = \dfrac{49}{12}$